In the prior art, it is known to use coaxial dielectric components to condition a signal being carried by a feed-through conductor. Such coaxial arrangements are expensive to manufacture, and do not readily allow for variations in the dielectric response to match differing needs. For example, if one customer desires a different response from the dielectric, it is often expensive to make the change, and may take an undesired amount of time.
To solve this problem, the prior art includes the use of two or more dielectrics, each dielectric being mounted to a substrate near the feed-through conductor. The inventor's previous patent application (U.S. patent application Ser. No. 12/116,776) provides for the use of one or more dielectric components in arrangements which increase the performance of this type of filter. However, improvements are still possible in the flexibility of design and ease of assembly of electromagnetic filters.